1. Field of the Invention
The invention relates to an injection molding process for producing components, particularly automotive parts, by injecting a thermoplastic melt into a mold, and to components that can be produced by means of this process. The components generally have the shape of a flat, bent, curved or buckled plate, whose edges can be straight or rounded. They can also have reinforcing ribs, apertures and mounting points. It is also possible that two plates are connected to each other by means of webs or struts, thereby forming a front wall and a rear wall.
2. Description of the Related Art
Automotive parts are often produced by means of injection molding of thermoplastics. In many cases it is necessary to strengthen a component in order to increase its rigidity and resistance to crash impact. Therefore, attempts have been made to place into the mold some plastic blanks containing endless fibers. However, it has turned out that the adhesion between the blanks and the injected thermoplastic is insufficient and that it is difficult to fix the blanks to the inner walls of the mold. Therefore, in order to obtain distortion-free components, two blanks have to be inserted into the mold, but this is technically difficult.
EP 0 378 854 A1 describes a process for producing a fiber composite material wherein a single fiber mat is impregnated with a plastic material in a closed mold. Thereafter, the mold halves are moved apart from each other, thereby leading to formation of cavities in the interior of the fiber mat. A molten polymeric material can then be injected into these cavities, albeit in a rather complicated manner.